40 y/o Athletic Woman: Motiva 350cc Demi Above Muscle—Round vs Ergonomix for Natural Results? (Photos)

I am 40 years old, 5'3", and approximately 125 lbs with a very lean, muscular, athletic build. I strength train regularly and compete in obstacle course races. Due to weight loss and becoming very lean, I have experienced significant breast volume loss, especially in the upper pole, with most of my remaining tissue sitting lower on the breast. My goal is to restore the volume I have lost and achieve a natural, proportional appearance. I do not want an obviously augmented or “permanent push-up bra” look, but I would like improved upper pole fullness. I still want a natural slope, softness, movement, and some natural drape. I will not be having a lift. My current surgical plan is a Motiva above-the-muscle augmentation, most likely a Demi profile around 350cc. Because of my athletic lifestyle and heavy weight training, I prefer to avoid under-the-muscle placement. My main decision is between Motiva Round and Motiva Ergonomix. My surgeon is leaning toward Round for better upper pole restoration and believes my existing lower pole tissue and lack of a lift will still allow a natural shape as the implant settles. I am drawn to Ergonomix because I like the idea of softer movement and a more gradual upper slope. Given my anatomy and goals, does a 350cc Demi seem appropriate for my frame, or does it sound too large? Would you recommend Round or Ergonomix to best achieve a natural but restored look?